In his first comments after the announcement of the nuclear accord between Iran and world powers, Iran’s supreme leader, Ayatollah Ali Khamenei, said Wednesday that the agreement needed “careful scrutiny.”

The deal between Iran and the United States, Britain, China, France, Russia and Germany is laid out in an extensive legal document that requires Iran to take several steps to provide more transparency of its nuclear program. In exchange, sanctions against Iran will be lifted in a step-by-step-process.